1. Field of the Invention
This invention relates to a method of making a ceramic article from a mixture containing clay and organic material. The invention also relates to ceramic articles e.g. bricks, made by this method.
2. Description of the Prior Art
In the manufacture of ceramic building materials, it is known to add organic residues such as straw to clay. The reason for this may for example be to improve the deformation properties of the clay mixture or to give it a certain desired porosity. However in the production of ceramic elements for the building industry by modern production methods, the addition of organic matter has as a result of certain disadvantages only found acceptance on a very limited scale.
It should be mentioned that ceramic elements in which sawdust is mixed as organic matter into the clay are known. Since the rise of the chipboard industry, however, the price of sawdust has risen considerably, making the production of bricks made of clay/sawdust mixtures very expensive. Additionally a very specially selected kind of clay is required for mixture with sawdust, which restricts the applicability of this known method.
It is also known to use expanded plastics material as an organic additive in a ceramic material. This too is a relatively expensive process, and the products lack strength.